[gst-devel] what format is exchanged between qtdemux and ffdec_h264

[Felipe Contreras]

On Thu, Oct 2, 2008 at 10:53 AM, franchan <francis.meyvis at gmail.com> wrote:
> Hello,
>
> I'm asked to create a gstreamer plug-in using a proprietary h264
> decoder library (binary only :-(.
> I based myself on the many gstreamer plug-ins.
> So implementing this until getting the chain function to work was smooth.
>
> Then now I'm blocked.
> The data that is passed from the qtdemuxer into the plug-in's chain function
> does not seem to contain any NAL headers or NAL unit.
> Can somebody explain what data format the qtdemux outputs?
>
> As a working reference I used this working pipeline:
> gst-launch filesrc location=small.mp4 ! qtdemu name demux
> demux.VIDEO_00 ! queue ! ffdec_h264 ! ffmpegcolorspace ! xvimagesink
>
> I dumped some GstBuffer data and I think it is part
> of the 'mdat' mp4 box for the mp4 container (small.mp4)
> What is passed to the ffdec_h264 is the same as what it passed to my
> plug-in wrapper.
> The proprietary decoder library hints that it does not understand the
> syntax of the content.
> I already tried to glue some 00 00 01 NAL prefix in front but
> this does not solve the problem.

Aside from raw frames the capabilities are also passed. Parts of the
capabilities is the codec-data, maybe that's what you want:
270000010fc2fe0af08f88800000010e18642bc23c80

-- 
Felipe Contreras